The present disclosure is related to a method for etching a protective film formed on a substrate using plasma. The present disclosure is also related to a method for producing a template that utilizes the protective film etching method and to a template which is produced by the method for producing a template.
In recent years, films having patterns of protrusions and recesses of photo masks for exposure and hard masks for etching, for example, are often produced by etching protective films formed by materials such as chromium or chromium oxide provided on substrates using plasma, accompanying decreases in processing dimensions.
The intensity of bias voltages in etching processes varies depending on the states of etching apparatuses during etching. Therefore, Japanese Unexamined Patent Publication No. 2007-193037, for example, discloses suppressing changes in a bias voltage in an etching process based on an aperture ratio of a pattern to be formed in the surface of a substrate and a predicted value of changes in reactance.